I am running two users at the same time because some games don't like compositing window managers, and you can't turn off compositing in Unity, my favored desktop. I don't want to run two TTYs of the same user because they interact with each other in unfortunate ways. I'm running Ubuntu 16.04.

One user, jonathan, is in a unity session in TTY7, the other, steamdude, is in an XFCE session in TTY2. Everything works as I want it to, except for audio. Once I added both users to the audio group and relogged, I could hear audio from one TTY while in the other TTY. However,
when one user is using the sound card, the other user can't play audio at all.

The closest to a solution that I have (and I don't know why it works), is using paprefs to enable an RTP device to loopback in the Unity session. steamdude don't need to connect to the RTP device; the loopback doesn't interfere with TTY2's sound for some reason. The problem is that there's a longstanding bug in module-loopback that causes it to have latency as long as a second. Manually looping with